Oxiracetam (Olaxiracetam) is a nootropic drug which was first synthesized by Smithkline Beecham (Italia) and launched to the market in 1987. (S)-oxiracetam is a single enantiomer with a chemical name of (S)-4-hydroxy-2-oxo-1-pyrrolidine acetamide racemate crystal form II (hereinafter referred to as “(S)-oxiracetam) and a chemical structure as shown below.

Oxiracetam is capable of promoting the synthesis of phosphorylcholine and phosphoryl ethanol, promoting brain metabolism, and providing a stimulating effect to specific central nervous pathway through blood brain barrier to improve the ATP/ADP ratio of the brain and enhance the synthesis of brain protein and nucleic acid, so as to improve the memory and learning ability of mentally retarded patients, and the drug itself is not vascular active or causes any stimulation to the central nervous system, but this drug has a persistent promoting effect on learning and memory.
P.R.C. Pat. Nos. CN1513836, CN1948285 and CN101121688 have disclosed methods for synthesizing a racemate composed of two isomers, respectively: L-oxiracetam and R-oxiracetam. P.R.C. Pat. Nos. CN101367757 and CN101575309 have disclosed methods for preparing L-oxiracetam. P.R.C. Pat. Nos. CN1424034, CN1555794, CN1562000 and CN101152175 have disclosed methods for preparing oxiracetam injection agent, dispersible tablets, and lyophilized as well as a new formulation. International Pat. No. WO 93/06826 has discloses a method for improving the treatment effect with regard to intelligence by oxiracetam. However, there is no report related to the levo-oxiracetam yet.